A broadband X-ray view of the ultraluminous sources in the galaxies ESO 501–023 and IC 5052

We report the results obtained from the analysis of XMM-Newton and NuSTAR observations of two ultraluminous X-ray sources (ULXs) located in the galaxies ESO 501–023 and IC 5052. To better understand their nature, we studied the spectral and timing behavior of these sources. We used spectral-timing techniques to investigate the presence of possible pulsations in the data. We did not detect any significant pulsations and set upper limits on the pulsed fraction of < 9% for ESO 501–023 ULX and < 11% for IC 5052 X-1. These sources exhibit typical ULX X-ray spectra and can be well fitted with two thermal components plus a Comptonization tail at high energies. To classify the sources, we compared their spectral parameters with those of other well-known ULXs. Our results show that ESO 501–023 ULX is in the broadened disk state and IC 5052 X-1 is in the hard ultraluminous state. Finally, our results suggest that the sources are likely nonmagnetic, supercritically accreting objects fed by companion stars.